[Checkins] SVN: z3c.form/trunk/ Allow overriding the "required" widget attribute using IValue adapter just like it's done for "label" and "name" attributes.

[Dan Korostelev]

Log message for revision 91268:
  Allow overriding the "required" widget attribute using IValue adapter just like it's done for "label" and "name" attributes.

Changed:
  U   z3c.form/trunk/CHANGES.txt
  U   z3c.form/trunk/src/z3c/form/widget.py
  U   z3c.form/trunk/src/z3c/form/widget.txt

-=-
Modified: z3c.form/trunk/CHANGES.txt
===================================================================
--- z3c.form/trunk/CHANGES.txt	2008-09-19 13:52:02 UTC (rev 91267)
+++ z3c.form/trunk/CHANGES.txt	2008-09-19 13:54:32 UTC (rev 91268)
@@ -5,6 +5,9 @@
 Version 2.0.0 (2008-??-??)
 --------------------------
 
+- Feature: Allow overriding the "required" widget attribute using IValue adapter
+  just like it's done for "label" and "name" attributes.
+
 - Refactoring: Use the ``z3c.pt.compat`` template engine compatibility
   layer.
 

Modified: z3c.form/trunk/src/z3c/form/widget.py
===================================================================
--- z3c.form/trunk/src/z3c/form/widget.py	2008-09-19 13:52:02 UTC (rev 91267)
+++ z3c.form/trunk/src/z3c/form/widget.py	2008-09-19 13:54:32 UTC (rev 91268)
@@ -65,7 +65,7 @@
     field = None
 
     # Internal attributes
-    _adapterValueAttributes = ('label', 'name')
+    _adapterValueAttributes = ('label', 'name', 'required')
 
     def __init__(self, request):
         self.request = request

Modified: z3c.form/trunk/src/z3c/form/widget.txt
===================================================================
--- z3c.form/trunk/src/z3c/form/widget.txt	2008-09-19 13:52:02 UTC (rev 91267)
+++ z3c.form/trunk/src/z3c/form/widget.txt	2008-09-19 13:54:32 UTC (rev 91268)
@@ -351,12 +351,31 @@
 sub-class are other options you might want to consider. Furthermore, you
 could also create a computed attribute value or implement your own component.
 
-Overriding any other attribtue, such as ``required``, is done in the same
+Overriding other attributes, such as ``required``, is done in the same
 way. If any widget provides new attributes, they are also overridable this
 way. For example, the selection widget defines a label for the option that no
 value was selected. We often want to override this, because the German
-translation sucks or the wording is often too generic.
+translation sucks or the wording is often too generic. Widget implementation
+should add names of overridable attributes to their "_adapterValueAttributes"
+internal attribute.
 
+Let's try to override the ``required`` attribute. By default the widget is required,
+because the field is required as well:
+
+  >>> ageWidget.required
+  True
+
+Let's provide a static widget attribute adapter with name "required":
+
+  >>> AgeNotRequired = widget.StaticWidgetAttribute(False, field=ageField)
+  >>> zope.component.provideAdapter(AgeNotRequired, name="required")
+
+Now, let's check if it works:
+
+  >>> ageWidget.update()
+  >>> ageWidget.required
+  False
+
 Overriding the default value is somewhat special due to the complexity of
 obtaining the value. So let's register one now: